In this paper, two new versions of modified active disturbance rejection control (MADRC) are proposed to stabilize a nonlinear quadruple tank system and control the water levels of the lower two tanks in the presence of exogenous disturbances, parameter uncertainties, and parallel varying input set-points. The first proposed scheme is configured from the combination of a modified tracking differentiator (TD), modified super twisting sliding mode (STC-SM), and modified nonlinear extended state observer (NLESO), while the second proposed scheme is obtained by aggregating another modified TD, a modified nonlinear state error feedback (MNLSEF), and a fal-function-based ESO. The MADRC schemes with a nonlinear quadruple tank system are investigated by running simulations in the MATLAB/SIMULINK environment and several comparison experiments are conducted to validate the effectiveness of the proposed control schemes. Furthermore, the genetic algorithm (GA) is used as a tuning algorithm to parametrize the proposed MADRC schemes with the integral time absolute error (ITAE), integral square of the control signal (ISU), and integral absolute of the control signal (IAU) as an output performance index (OPI). Finally, the simulation results show the robustness of the proposed schemes with a noticeable reduction in the OPI.

In this work, a Nonlinear Higher Order Extended State Observer (NHOESO) is presented to replace the Linear Extended State Observer (LESO) used in Conventional Active Disturbance Rejection Control (C-ADRC) solutions. In the NHOESO, the standard LESO is completed with a two-term smooth nonlinear function with saturation-like characteristics. The proposed novel NHOESO enables precise observation of the generalized disturbances with higher-order derivatives. The stability of the NHOESO is examined with the aid of the Lyapunov method. A simulation of an uncertain nonlinear Single-Input–Single-Output (SISO) system with time-varying external disturbances confirms that the proposed NHOESO copes well with the generalized disturbance, which is not true for other ESOs.

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The deflection and deformation behaviour of a 30% weight fraction glass-polyester sandwich panel was studied as a function of graphite filler quantity and impact velocity. Experiments based on Taguchi methods were carried out in order to collect data systematically. The panel is fastened on three sides and left free for the destructive test. By applying the impact force. The vibration data collector is used to measure the deflection (TVC 200). During the destructive test, the panel is additionally fastened to a solid base for stability. The steel hammer came crashing down from above. A Vernier calliper is used to measure the distortion. The tests were planned using Taguchi's L9 orthogonal array method. Examine the effects of impact force, height, and graphite filler content on low-velocity deflections and deformations using analysis of variance. The findings demonstrate that the mass is the primary parameter influencing the deflection, whereas the graphite filler is the primary parameter influencing the deformation. As a last step, a confirmation tests have been run to make sure the predicted experimental outcomes from those correlations were correct.